def test_reverse(self):
"""
Tests the SinglyListedList.reverse() method
"""
linkedList = SinglyLinkedList()
linkedList.push(0)
linkedList.push(1)
self.assertEqual(linkedList.to_list(), [0, 1])
linkedList.reverse()
self.assertEqual(linkedList.to_list(), [1, 0])
linkedList.reverse() # back to [0, 1]
linkedList.push(2) # now [0, 1, 2]
self.assertEqual(linkedList.to_list(), [0, 1, 2])
linkedList.reverse()
self.assertEqual(linkedList.to_list(), [2, 1, 0])
linkedList = SinglyLinkedList()
linkedList.push(0)
linkedList.push(1)
linkedList.push(2)
linkedList.push(3)
linkedList.push(4)
linkedList.push(5)
self.assertEqual(linkedList.to_list(), [0, 1, 2, 3, 4, 5])
linkedList.reverse()
self.assertEqual(linkedList.to_list(), [5, 4, 3, 2, 1, 0])
def test_push(self):
"""
Tests the SinglyLinkedList.push(data) method
"""
linkedList = SinglyLinkedList()
# push first Node
linkedList.push('node zero')
self.assertEqual(linkedList.length, 1)
self.assertIsInstance(linkedList.head, Node)
self.assertIsInstance(linkedList.tail, Node)
# push second Node
linkedList.push('node one')
self.assertEqual(linkedList.length, 2)
self.assertEqual(linkedList.head.data, 'node zero')
self.assertEqual(linkedList.tail.data, 'node one')
self.assertEqual(linkedList.head.next.data, 'node one')
def test_shift(self):
"""
Tests the SinglyListedList.shift() method
"""
linkedList = SinglyLinkedList()
linkedList.push(0)
linkedList.push(1)
linkedList.push(2)
# shift node with data 0 from [0, 1, 2]
shifted = linkedList.shift()
self.assertIsInstance(shifted, Node)
self.assertIsNone(shifted.next)
self.assertEqual(shifted.data, 0)
self.assertEqual(linkedList.head.data, 1)
self.assertEqual(linkedList.tail.data, 2)
self.assertEqual(linkedList.length, 2)
# shift node with data 1 from [1, 2]
shifted = linkedList.shift()
self.assertIsInstance(shifted, Node)
self.assertIsNone(shifted.next)
self.assertEqual(shifted.data, 1)
self.assertEqual(linkedList.head.data, 2)
self.assertIsNone(linkedList.head.next)
self.assertEqual(linkedList.tail.data, 2)
self.assertIsNone(linkedList.tail.next)
self.assertEqual(linkedList.length, 1)
# shift node with data 2 from [2]
shifted = linkedList.shift()
self.assertIsInstance(shifted, Node)
self.assertIsNone(shifted.next)
self.assertEqual(shifted.data, 2)
self.assertIsNone(linkedList.head)
self.assertIsNone(linkedList.tail)
self.assertEqual(linkedList.length, 0)
# shift empty list
shifted = linkedList.shift()
self.assertIsNone(shifted)
self.assertIsNone(linkedList.head)
self.assertIsNone(linkedList.tail)
def test_get(self):
"""
Tests the SinglyListedList.get(index) method
"""
linkedList = SinglyLinkedList()
linkedList.push(0)
linkedList.push(1)
linkedList.push(2)
# check index of out bounds returns None
self.assertIsNone(linkedList.get(-1))
self.assertIsNone(linkedList.get(3))
# test indices
self.assertEqual(linkedList.get(0).data, 0)
self.assertEqual(linkedList.get(1).data, 1)
self.assertEqual(linkedList.get(2).data, 2)
# last
self.assertEqual(linkedList.get(linkedList.length - 1).data, 2)
def test_pop(self):
"""
Tests the SinglyListedList.pop() method
"""
linkedList = SinglyLinkedList()
linkedList.push('node zero')
linkedList.push('node one')
linkedList.push('node two')
self.assertEqual(linkedList.length, 3)
popped = linkedList.pop()
self.assertEqual(popped.data, 'node two')
self.assertEqual(linkedList.length, 2)
popped = linkedList.pop()
self.assertEqual(popped.data, 'node one')
self.assertEqual(linkedList.length, 1)
popped = linkedList.pop()
self.assertEqual(popped.data, 'node zero')
self.assertEqual(linkedList.length, 0)
popped = linkedList.pop()
self.assertIsNone(popped)
self.assertEqual(linkedList.length, 0)
def test_delete(self):
"""
Tests the SinglyListedList.delete(index) method
successful delete returns true, else false
"""
linkedList = SinglyLinkedList()
# can not delete from empty list
self.assertFalse(linkedList.delete(0))
# can delete from list with single item
linkedList.push(1)
self.assertEqual(linkedList.to_list(), [1])
self.assertTrue(linkedList.delete(0))
self.assertEqual(linkedList.to_list(), [])
linkedList.push(1)
linkedList.push(2)
linkedList.push(3)
# can not delete index out of bounds
self.assertEqual(False, linkedList.delete(-1))
self.assertEqual(False, linkedList.delete(999))
# can delete tail, index 2
self.assertEqual(linkedList.to_list(), [1, 2, 3])
self.assertTrue(linkedList.delete(2))
self.assertEqual(linkedList.to_list(), [1, 2])
linkedList.push(3)
self.assertEqual(linkedList.to_list(), [1, 2, 3])
# can delete middle, index 1
self.assertTrue(linkedList.delete(1))
self.assertEqual(linkedList.to_list(), [1, 3])
# can delete tail
self.assertTrue(linkedList.delete(1))
self.assertEqual(linkedList.to_list(), [1])
# can not delete out bounds
self.assertFalse(linkedList.delete(1))
self.assertEqual(linkedList.to_list(), [1])
# can delete index 0
self.assertTrue(linkedList.delete(0))
self.assertEqual(linkedList.to_list(), [])
def test_clear(self):
"""
Tests the SinglyListedList.reverse() method
"""
linkedList = SinglyLinkedList()
linkedList.push(0)
linkedList.push(1)
linkedList.push(2)
linkedList.push(3)
linkedList.push(4)
linkedList.push(5)
self.assertEqual(linkedList.to_list(), [0, 1, 2, 3, 4, 5])
self.assertIsInstance(linkedList.clear(), SinglyLinkedList)
self.assertEqual(linkedList.to_list(), [])